The present invention relates to an ozone decomposing material for decomposing ozone and an ozone decomposing apparatus using the ozone decomposing material, which can be employed, for instance, not only in electrostatic coping machines provided with a corona charger and laser printers, but also in waterworks and sewerage systems, and an apparatus for activating the surface of synthetic resin films for improving the ink receptivity and adhesiveness thereof.
Ozone is generated, for instance, in the above-mentioned apparatus and is toxic to humans when breathing air containing more than 0.1 ppm of ozone for a long period of time. According to the safety standards for ozone to humans proposed by Japanese Association of Industrial Health, ACGIH (American Conference of Governmental Industrial and Hygienists), and OSHA (Occupational Safety and Health Administration), the permissible maximum average concentration of ozone in the air is 0.1 ppm when breathing the air for 8 hours. Many apparatus for industrial use are produced by observing these standards. Ozone has a characteristic pungent odor, and the odor is noticeable even at concentrations as low as 0.01 to 0.02 ppm. Some operators of an industrial apparatus which generates ozone at such concentrations may complain about the odor. When the concentration amounts to about 0.05 ppm, it has an unpleasant odor, and when the concentration exceeds 0.1 ppm, it is irritating to mucus membranes of the eyes and respiratory organs.
Further, ozone is a powerful oxidizing agent which oxidizes and deteriorates organic materials. Therefore, it is desirable that the concentration of ozone be as low as possible, not only to humans, but also to industrial apparatus and devices.
Conventionally, various ozone decomposing materials and ozone decomposing apparatus have been invented. However, when preparing an ozone decomposing apparatus is made, the ozone decomposing performance, the pressure loss and the flow rate of the air from which ozone is eliminated, the humidity conditions, and the deterioration of the ozone decomposing material with time, have to take into consideration. However it is extremely difficult to make an ozone decomposing apparatus and an ozone decomposing material which satisfy the above-mentioned conditions as a whole.
Electrophotographic copying machines including a corona charger and air cleaners generate ozone at low concentrations. Most of them are provided with an ozone decomposing apparatus in the shape of a filter, in which an ozone decomposing member made of, for instance, an activated carbon filter, is employed.
However, the concentration of the ozone generated in the currently employed PPC is about 1 ppm or less and a honeycomb-like activated carbon filter for decomposing the ozone at such low concentrations deteriorate with time to a not negligible extent and lasts only for several months.
Further a large size corona charger for activating the surface of a resin film, and sterilization apparatus using an ultra-violet light source and decolorization apparatus generate ozone at high concentrations. For decomposing ozone at a high concentration, a large amount of granular active carbon, metal catalysts, organic compounds such as manganese dioxide, and mixtures thereof are employed. However, the ozone decomposing performance of these agents is not yet satisfactory.
Furthermore, when a variety of filters such as activated carbon filter and Hopcalite filter are employed, the air containing ozone has to be passed through such a filter. When the density of the filter is increased, the ozone absorption and decomposition performance is also increased. However, the air cannot be passed through the filter smoothly, since the pressure loss is increased as well. As a result, the problem is caused that the problem is caused that the temperature within the apparatus including the ozone decomposing filter is disadvantageously elevated. The elevation of the temperature within the apparatus will eventually shorten the life of the apparatus.
On the contrary, when the density of the filter is decreased, the ozone adsorption and decomposing performance is also decreased.
In any event, it is necessary to provide a powerful suction apparatus or blower in order to cause the ozone-containing air to pass through the filler. However, such suction apparatus or blower causes noise. Furthermore, in order to minimize the elevation of the temperature within the ozone generating apparatus, a cooling apparatus is also necessary, so that apparatus including the conventional ozone decomposing apparatus is costly as a whole. Further there is a demand for a small size, powerful ozone decomposing apparatus for use in the activation of the surface of resin films and sterization apparatus. However, such a demand is not yet met.